[patch 08/43] ALSA: hda - Fix DMA mask for ATI controllers

From: Greg KH
Date: Fri Mar 20 2009 - 19:28:57 EST


2.6.28-stable review patch. If anyone has any objections, please let us know.

------------------

From: Takashi Iwai <tiwai@xxxxxxx>

commit 09240cf429505891d6123ce14a29f58f2a60121e upstream.

ATI controllers (at least some SB0600 models) appear buggy to handle
64bit DMA. As a workaround, reset GCAP bit0 and let the driver to
use only 32bit DMA on these controllers.

Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
sound/pci/hda/hda_intel.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -2208,9 +2208,17 @@ static int __devinit azx_create(struct s
gcap = azx_readw(chip, GCAP);
snd_printdd("chipset global capabilities = 0x%x\n", gcap);

+ /* ATI chips seems buggy about 64bit DMA addresses */
+ if (chip->driver_type == AZX_DRIVER_ATI)
+ gcap &= ~0x01;
+
/* allow 64bit DMA address if supported by H/W */
if ((gcap & 0x01) && !pci_set_dma_mask(pci, DMA_64BIT_MASK))
pci_set_consistent_dma_mask(pci, DMA_64BIT_MASK);
+ else {
+ pci_set_dma_mask(pci, DMA_32BIT_MASK);
+ pci_set_consistent_dma_mask(pci, DMA_32BIT_MASK);
+ }

/* read number of streams from GCAP register instead of using
* hardcoded value


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